I am using WordPress 1.51 and Firefox 1.5 and above has consistently been having trouble handling some of the WordPress scripts. Currently, I can't add links with it at all -- it's got some kind of problem with link-add.php, which does work fine in Internet Explorer.
However, I am unable to use performancing in Internet Explorer along with many other WordPress extensions I have installed.
With previous difficulties, I was able to solve the problem by uninstalling firefox, deleting every .xpi and firefox file off my drive and ultimately, re-installing Firefox to a separate drive.
I haven't gone quite that far yet with link-add, but I have uninstalled most of my extensions.
All the other 'buttons' seem to work now -- including 'add category', but with 'add link,' I can see something flash by too fast for me to actually see it, then a completely blank browser window/tab pops up.
If anybody in here has any idea at all as to how I can fix it so Firefox can handle links with WordPress, or knows of additional places where I should look for help (I've already searched the Firefox forum along with this one), I'd be extremely grateful.